ATMEGA8_14 Datasheet, PDF (71/331 Pages) ATMEL Corporation – High-performance, Low-power Atmel

ATmega8(L)
Figure 28. Timer/Counter Timing Diagram, No Prescaling
clk_I/O
clk_Tn
(clk_I/O/1)
TCNTn
MAX - 1
MAX
BOTTOM
TOVn
BOTTOM + 1
Figure 29 shows the same timing data, but with the prescaler enabled.
Figure 29. Timer/Counter Timing Diagram, with Prescaler (f_{clk_I/O}/8)
clk_I/O
clk_Tn
(clk_I/O/8)
TCNTn
MAX - 1
MAX
BOTTOM
TOVn
BOTTOM + 1
8-bit
Timer/Counter
Register
Description
Timer/Counter Control
Register – TCCR0
Bit
7
6
5
4
3
2
1
0
–
–
–
–
–
CS02
CS01
CS00
TCCR0
Read/Write
R
R
R
R
R
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
• Bit 2:0 – CS02:0: Clock Select
The three clock select bits select the clock source to be used by the Timer/Counter.
71
2486AA–AVR–02/2013